Fix a false positive for Style/RequireOrder

This PR fixes a false positive for `Style/RequireOrder`
when single-quoted string and double-quoted string are mixed.

changelog/fix_a_false_positive_for_style_require_order.md

@@ -0,0 +1 @@
+* [#11902](https://github.com/rubocop/rubocop/pull/11902): Fix a false positive for `Style/RequireOrder` when single-quoted string and double-quoted string are mixed. ([@koic][])

lib/rubocop/cop/style/require_order.rb

@@ -106,8 +106,9 @@ def find_previous_older_sibling(node) # rubocop:disable Metrics
             break unless sibling&.send_type? && sibling&.method?(node.method_name)
             break unless sibling.arguments? && !sibling.receiver
             break unless in_same_section?(sibling, node)
+            break unless node.first_argument.str_type? && sibling.first_argument.str_type?
 
-            node.first_argument.source < sibling.first_argument.source
+            node.first_argument.value < sibling.first_argument.value
           end
         end
 

spec/rubocop/cop/style/require_order_spec.rb

@@ -8,6 +8,13 @@
         require 'b'
       RUBY
     end
+
+    it 'registers no offense when single-quoted string and double-quoted string are mixed' do
+      expect_no_offenses(<<~RUBY)
+        require 'a'
+        require "b"
+      RUBY
+    end
   end
 
   context 'when only one `require`' do